Rock-drill.



T. E. STURTEVANT.

I ROCK DRILL. APPLICATION FILED APR-2|..I9I7- Patented May 7,1918.

3 $HEET8-SHEET l- T. E. STURTEVANT.

ROCK DRILLL APPLICATION FILED 4mm, new. I

3 SHEETS-SHEET 2.

Pawn-te May 1918.

T. E; STURTEV'A NT. ROCK DRILL. .AP PLICATION FILED APR.2I. 19H.

Patnted I ma 7,1918;

a swimsu t INVENTOR rock drilling? engines which are known enemas E. S'llll'fiillillidllill, 631* IDGVER, NEW JERSEY, ASSIGNOR T0 MoKIERNAN-TERRY IDEILL CQMPfslll'Y, tilt dltt, NLEW FER/S Y, CQRPOEATION QF NE? JERSEY.

EUCK IBEZL'L.

ilg'in'licatlon filed front 21, 1917.

To all whom it may concern:

Be it known that l, Trioii/ls Srnnrn- Vance, a citizen of the United ti tatcs of Alnel'ltih, and a resident of Dover. llllorris county, and State of New Jer ey. have in vented certain new and useful improvements in ltockdJrills. of which the following is a specification, reference being had to the accompanying drawings, forming" a part thereof.

My invention relates to improvements rock drills, and especially to that type in of as hannncr drills. Its object is to provide a simple and efi'icient apparatus of this kind of rugged construction.

rino'ther object is to improve upon the valve mechanism and to simplify and shorten the fluid passages, and to provide a simple arrangement for automatically can rying the valve past its central posit-ion.

In. order that my invention may be thoroughly understood I will now proceed to doscribe the same in the following specification and then point out the novel features thereof in appended claims.

Referring to the drawings:

Figure 1' is a sectional side elevation of a hammer drill made according to and embodying the present invention.

Fig. 2 is a front elevation of the same apparatus.

Fig.1. 3 is a sectional side elevation of the valve n'xcchanisn'i on a larger scale.

. Fig. 4.1 is a sectional front elevation of the same mechanism.

Figs. 5, G. 7. 8. 9, l0 and 11 are recticnal plan views of the valve mechanism, these sections being taken respectively on the lines 5 5, s -c. 7-7, a e, 9 a, 1040 and l.l-ll of Fig. 3.

Fig. 12 is another detail of constructioin this figure showing the rear end of the valve casing in elevation.

Fig. 13 is a diagram showing the valve, cylinder and piston and the coactin r ports and passages.

Like characters reference designate corresponding parts in all the figures.

9.0 is the main casing and is constructed with two longitudinal bores 21 and The bore 21 forms the main cylinder of the en gine and 2'2 a valve casing chamber. A. rear cylinder head 23 fits over this casino; and into the cylinder 21. comprises a ea fineeificstieu of Letters Patent,

Patented May "I, 1918.

Serial No. waste.

of smaller diameter than that of the cylinder 21, which extends into this cylinder. It is constructed to form "primary lugs 25 which project laterally in line with the cylinder- 21, and Wlllll secondary lugs 26 which project laterally in line with the valve chainher here 22. It is provided with a port with which an air or water pipe may be connected and which leads to a central chamber 27, and with, a threaded fluid pressure intake port 28 directly over the valve casing chamber.

The forward cylinder head is designated by 30. This fits into the main cylinder and oyer the valve casing chamber. Opposite the latter chamber it forms laterally projecting logs 31 in line with the lugs 26, and between them is a threaded exhaust port 32. In line with cylinder 21 this forward head is provided with a longitudinal opening through which the piston extension '21 slides.

On the forward end of this cylinder head is a round boss 8-12 with its axis coincident with the axis of the main cylinder, over which boss fits the forward sleeve Within which certain parts of the apparatus are supported. The rear portion of this sleeve is constructed to form projecting lugs 36 in. alinenient with the lugs 25.

40 is a handle bar from W iich extend supports 41 to a frame 42 which rests upon the rear cylinder head 23 and has holes therein which coincide with similar holes in thelugs 25. The main parts of the apparatus are held together by through-bolts 4-3 which pass through the handle bar frame, lugs 25 and 36. and have nuts ll on their outer ends. Between the nuts 4-1 and the for \ard side of lugs 36 compression springs 45 are interposed.

Asimilar arrangement is used to hold the rear and forward cylinder herds against adjacent ends of the valve chamber. In this case the through-bolts which are designated by ltlrpass through the lugs 26 and 31; their nuts are designated oy 47 and the compression springs by 48.

Inside of the front sleeve 35 which is thus connected. with the main part of the apparatus. is a rotary sleeve 50. The rear end of this is of larger internal diameter than the P9890113 it and is provided With a ring of ratchet teeth 51. A pawl ring: 52 is placed within this part of enlarged internal diameter and supports pawls 53 which are springpressed into engagen'icnt with the ratchet teeth 51. The pawl ring is provided with a central opening through which the piston extension 71 slides, which is substantially cylindrical in cross section except for two diametrically opposed ribs 54 which project into this opening and into inclined grooves in the piston extension, by means of-which it is oscillated by the reciprocations ot' the piston extension.

The forward end of the rotary sleeve 50 is cut back to form alternate projections 56 and depressions 60 is a drill bit socket having a polygonal bore 61 adapted to receive a similarly shaped socket of a drilling tool (not shown). This is rotatively supported Within the forward sleeve 35 and has an enlarged head 62 which rests upon a shoulder within the forward sleeve to pre vent the drill bit socket from falling out. The rear end of the head 62 is constructed with. depressions 63 into which the projections 56 on the forward end of rotary sleeve 50 extend, and with projections 59 which extend into the depressions 57.

64 is an anvil Dlock within the rotary sleeve 50 and slidable therein. its rear 'ard movement is limited by an integral enlarged head (35 which. abuts against an annular shoulder 58 formed inside of sleeve 50. he anvil block is also provided with a central axial hole 66.

70 is the piston and 71 an integral extension thereof. The rear end of the piston is provided with a recess 72 to permit the piston in its travel to pass over the lug 24:. In the piston extension are two diametrically opposed longitudinal grooves into which fit ribs projecting from the forward cylinder head 30. to hold the piston. against rot-ation. These parts are not shown as they form no part of this invention and arevlell known. There is a hole 7 3 through the cen ter of the piston and piston extension.

74 is a tube, the rear end of which is flanged and held in place by a threaded lug 75 screwed into the rear cylinder hea 23. The end of this plug is slotted at 7 6 to pen mit the passage of air or Water from the chamber 27 to the tube 74. This tube passes through the piston and piston extension and its forward. end is reduced in diameter as shown at '77 to pass through the hole 66 in the anvil block and into a hole through the on center of the drill bit, it being understood that when this tube is is used, hollow.v drill bits are to housed with the apparatus.

I The valve casing is a cylindrical body arranged to fit into the valve chamber 22. In the particular form shown the valve casing is made of a rear art and a forward part designated respectively by 80 and 81, both slotted on one side and held in alinement by the wall of the valve chamber and in proper axial relation by means of a key messes 82 titted into these slots and another slot in the wall of the valve chamber.

Through the center of the valve casing is a bore 83 and or. each end thereof alining bores S*i-S5 of smaller diameter. 86 is a fluid pressure supply chamber formed in the rear end of valve casing) member 80, and 87 is an exhaust chamber formed in the for ward valve casing; member 81. S8 and 89 are hollow screw plugs in the main casing :20 at the ends of the valve casing and adjacent the intake opening 28 and the exhaust opening" 32 respectively.

il ilhin the valve casing is a reciprocatory valve which comprises three intermediate rings or pistons 9091 and 99 of a diameter to make a sliding it in the bore 83, and two end rings or pistons 939- l of a diameter to make a sliding These rings or pistons are equally spaced and are integral with a central spindle 95 which extends a short distance beyond the end rings as at 96 and 97.

The outer wall of the valve casing is cut away for the greater part of its length as at 100 to form a passage which isconnected by ports 101 with supply chamber 86.

A port 102 connects passage 100 with the interior of the valve casing part 80, and another port 103 connects the same passage with the interior of valve casing part 81.

On another side thevalve casing is cut away in a similar manner as at 104. to form a passage for the exhaust and this is connected by ports 105 with the exhaust chann ber 87. A port 106 connect-s passage lO-l with the central part of the interior of the valve casing. 107 is a port between exhaust passage 10% and the interior of the smaller bore 84 about midway of its length. From Lhe other smaller bore 85 is a similar port 108 leading to exhaust passage 164.

The valve pistons and ports are so proportioned and arranged that when the valve is in its central position, its pistons 90, 91, 92, 93 and will register with and close ports 102, 106, 103, 107, 108 respectively. The valve pistons and ports are of the same width so that a movement of the valve from its central position in either direction, will open all of these ports.

107 is a narrow extension oi port 107 on the rear side thereof, and .108 is a similar extension of port 108 on the forward side thereof. Thus when the valve is in its central position to close all of the ports, both of these port ei ztensions are open.

Between the passages 100 and 104 the rear part 80 of the valve casing is cut away at 110 to form a passage from the interior of the valve casing to the rear part of the main cylinder 21. A port 111 connects this passage With the interior of the valve casing. The forward part-81 of the valve casing is cut away as at 11:2 to form a passage fit in the bores 84 and 85.

from the interior of the valve casing to the forward part or the, menu cylinder. This passage is connected with the interior of the valve easing by means of a port 113. 114 designates main ports through main casing 20 hetween the rear end or the main cylin der 2i. into the valve chamber 22 communicating; with passage 110. 115 are ports through main casing'hetween the forward end of the main cylinder to the valve chamher communicating with-the passage 112.

A. groove 120 is cut in the wall of the valve casing part 80 between passages 104 and 110 and hole 121 is drilled from the groove into the rear end of the interior of the valve casing. 12-2 is a port through the main casing between the main cylinder and the groove 120.

123 is a similar groove in valve casing member 81; 12 k a hole leading therefrom to the forward end or" here 85, and 125 a port through the main casing between the main cylinder and the groove 123.

The operation of the device is as follows :Assu1ning that fluid pressure such for example, compressed air, is supplied to the device through. the port 29, the reciprocatory valve is in the position in which it is shown in the drawings, and that the main piston is at the rear end of its stroke, the

p: 10 \i' h communicates through polio with J3 exhaust port 32 to the atmosphere. This will cause the piston 70 to be pushed r vard.

is soon as the main piston reaches such a position that its rear edge will uncover port 122, the pressure of the fluid within the main cylinder will pass through this port into the groove and through the hol 121 into the rear the valve casin hack of the rear piston 93. This will ilt in the liuid pressure acting upon the rear surface of the piston 03 and the valve will he pushed forward thereby against. the pressure which. through port 103 is present between the spools 02 and 9d, the ditierence in area between. two spools having been depended upon to hold the valve in its rest]: position up to this point of the operation.

When the reciprocatory valve reaches its central position, its p ston closes port 103 to cut oil pressure supply between pistons 02 and 94 itspiston 03 will close port 107 g valve, will be reduced, enough of this pressure-Will remain to insure the further forward movement of the valve.

Further movement of the valve will cause piston 90 to open port 102 to introduce pressure hack of piston 90 to cause the valve to continue its stroke. As soon as piston 90 begins to open port 102, piston 93 will begin to open port 107 to release the pressure back of piston 93. When the valve has completed its forward movement piston 91 will have fully crossed port 106 so that there is free escape of pressure from the rear end of the main cylinder to the atmosphere, and piston 90 willhaveiully crossed port 102 to admit pressure to the forward side of the main. piston. Under these conditions the main. piston will he moved back.

During. the forward movement of the valve, the port extension 108 will delay the closing of the OutlGt fIO111 the space within bore 85 so that a smaller amount of air will he entrapped within this space than would be if the port extension were not present. This results in diminishing the cushioning eltect of the air entrapped in this space.

The main piston will then continue its forward movement until i reaches the end of its stroke. The reciprocatory valve has, as just described, been forced forward so that the fluid pressure supply is now admitted through passages 100 through port 103 between valve pistons 91 and 92 through-port 113, passage 112, and ports 115 to the part of the main cylinder forward of the main piston. At the same time the passage has been opened through the rear end of the main cylinder through ports 114:, passage 110, port 111, between valve spools 90 and 91, through port 111., throughport 106 to exhaust passage 104. This will cause the main piston to he forced rearwardly.

As soon as it reaches such a position that the forward edge of the main piston '70 uncovers port 125, fluid pressure therein will he admitted to the forward end of the interior of the valve casing through the hole 12% to force the reciprocat'ory valve rearwardly in a similar manner to that already.

described for the forward stroke.

The shank of the drill bit is of suiiicient length to extend beyond the socket 60 into When it is desired to use a cleansing fluid,

such as air or water, or both, this fluid is led into the chamber 27 and has free 00111 munication through the slot Y6 with the in terior of tube '?-l,the forward narrowed. porion 77 of which extends into a hole of the drill bit so that the desired cleaning fluid will be forced directly through the drill bit into the bottom of the hole being drilled.

This drill has the advantage of having all of its fluid passages short and direct, its

valve action is very quick acting and gives the apparatus a high ei'ficiency The Whole construction is ru ged and simple. It is not my intention to limit myself to the exact construction shown which is merely illustrative of a preferred form of construction, but intend only such limitations as are imosed by the following claims.

'What I claim is 1. A rock drill. comprising a cylinder, a piston therein, a valve casing having a central chamber with cylinder ports connected with the ends of the cylinder beyond the ends of the piston travel and having pressure and exhaust ports, said valve casing also having end chambers of less area than that of the central chamber, passages from the cylinder within the ends of the piston travel to the'ends of the corresponding end chambers, a reciprocatory valve in all of said chambers arranged to be moved beyond its central position by motive fluid from the cylinder through said passages, and arranged to alternately connect the cylinder ports withthe supply and exhaust ports, a relief port in said end chambers intermediate the ends thereof, each of said relief ports having a port extension of less area than that of said passages arranged to be opened by the valve in its central position to allow a part of the valve actuating fluid to escape from the end chambers.

2. A roclr drill comprising a main cylinder and a piston therein, a valve casing having a central bore with cylinder ports con nected with the ends of the main cylinder beyond the ends of the piston travel, and

having pressure and exhaust ports, said valve casing also having" alining end bores of smaller diameter, passages from the main cylinder within the ends of the piston travel to the ends of the corresponding end bores,

and a piston valve comprising end pistons fitting the end bores and intermediate pistons fitting said central bore spaced from said end pistons and from each other, relief ports in the end hores intermediate their ends, each of said relief ports having a port extension of less area than that of said pas sages, on the sides of the relief ports toward the ends oi the end bores.

3. A rock drill comprising a'main cylinder and a piston therein, a valve casing having a central bore with cylinder ports connected with the ends of the main cylinder till beyond the ends of the piston travel, and

having pressure and exhaust ports, said valve casing also having alining end bores of smaller diameter, passa es from the main cylinder Within the ends 0 the piston travel to the ends of the corresponding end bores, and a piston valve comprising end pistons fitting the end cores and intermediate pistons fitting said central bore spaced from said end pistons and from each other, relief ports in the end bores intermediate their ends, said pistons being arranged to close all of said ports when the valve is in its central position and to open all ofsaid portswhen the valve is moved in either direction from its central position, each or" said relief ports having a port extension of less area than that of said passages, on the sides the relief port-s toward the ends of the en;

bores, said valve pistons being so arranged 

